Vertical lines powder coating aluminum profiles

Introduction

In modern construction are widely used aluminum profiles with powder coated. These aluminum profiles particularly high demands on their appearance and durability. The thing is, that the painted surface defects and damage to the aluminum profiles, which are part of large construction and architectural design, not so easy to repair or repaint. At the same time, These profiles are subjected to severe climatic and weather resistant, including, solar radiation, rain and large temperature swings. All of this means, that painted aluminum profiles must maintain its attractive appearance over a long period of very difficult conditions.

Aluminum profiles with powder coating

Therefore, the production of colored aluminum profiles requires the highest possible level of quality powder coating process. This requires a thorough quality control, process both the powder coating, and the finished powder coating aluminum profiles.

A feature of the construction and architectural aluminum is a wide variety of colors of the powder coating. Therefore, powder coating manufacturers should be prepared for frequent changes of paint on its paint lines.

Design of modern buildings require an increased length of aluminum profiles. Until recently, the standard length was aluminum profiles 6 m. Currently, builders are increasingly needed length profiles 7 m, and even 7,5 m, for example, for front struts, which are installed directly on the two floors of the building.

The types of powder coating lines

The choice of powder coating line for each enterprise depends on many factors. These factors include the annual production profiles, размеры производственных помещений (площадь, length, высота), the number of profiles in batches, color change frequency, the possibility of coloring of products of different sizes and from different materials, and the like.

Regardless of the type lines, каждая из них должна включать необходимые технологические этапы:

  • химическая подготовка поверхности профилей;
  • сушку профилей после химической подготовки;
  • электростатическое нанесение порошковой краски на профили;
  • обработка порошкового покрытия в печи полимеризации;
  • охлаждение профилей после печи полимеризации;

Manufacturers of equipment for powder coating, including, aluminum profiles, They offer various types of painting lines. for instance, известная фирма EUROIMPLANTI (Италия) [1] производит несколько типов окрасочных линий в различных вариантах по производительности и компоновке оборудования с учетом конкретных требований заказчиков.

Линии порошкового окрашивания могут отличаться друг от друга:

  • по ориентации алюминиевых профилей в процессе обработки: горизонтальные и вертикальные линии;
  • по способу напыления порошка – автоматические и ручные;
  • по методу подготовки поверхности – хроматные и бесхроматные;
  • непрерывные и с разделением на подготовку поверхности и собственно окраску;
  • по расположению технологического оборудования – в одном уровне или в два уровня («компактные» линии).

Методы загрузки и выгрузки профилей зависят от типа окрасочной линии:

  • на непрерывных автоматических линиях профили загружаются в начале линии (перед химической подготовкой), а выгружаются уже с готовым порошковым покрытием после обработки в печи полимеризации и охлаждения;
  • малые линии могут иметь отдельные этапы химической подготовки в горизонтальных ваннах; на следующем этапе профили навешиваются на конвейер для собственно порошкового окрашивания.

Vertical powder coating line

Первые вертикальные линии порошкового окрашивания появились в Италии еще в 1980-е годы [2]. Therefore, the Italian manufacturer of this equipment have great credibility all over the world. These lines are ideal for large-scale production of aluminum profiles with multiple extrusion presses. These lines can vary in performance, on the conveyor speed, by area, все они состоят из связанных между собой отдельных модулей:

  • baseline profiles loading and unloading zone of finished profiles, обычно совмещаются в одной зоне;
  • туннель химической подготовки поверхности профилей;
  • печь сушки профилей после химической подготовки перед нанесением напылением на них порошка;
  • печь полимеризации для химического соединения различных компонентов порошковой краски в прочное порошковое покрытие;

An example of a typical arrangement of a vertical line equipment powder coating aluminum profiles shown in Figure 1.

Figure 1 - The scheme of a typical vertical line powder coating
(линия EuroFlex итальянской фирмы EUROIMPLANTI [2]):
1 - download, 2 - tunnel surface preparation, 3 – drying oven,
4 - powder spray booth, 5 - a polymerization oven, 6 – unloading

Loading profiles

A general view of the loading area is shown in Figure 2. Profiles are supplied to the horizontal table loading zone. One end of each profile previously provided with an opening. In the hole insert a special hook, который соединен с главным конвейером линии (рисунок 3). In the course of the conveyor profile is gently raised from its horizontal position to a vertical position. Further, the conveyor carries the profiles of all the working operations of the line - chemical processing, dried, spraying powder and a powder of polymerization.

Figure 2 - General view of the vertical line feed zone
порошкового окрашивания алюминиевых профилей [2]

 

Figure 3 - System attaching aluminum profiles
на конвейер вертикальной линии порошкового окрашивания [2]

Tunnel surface preparation profiles

Tunnel chemical preparation of profiles represents a number of separate sections, в нижней части которых расположены ванны (резервуары) с различными рабочими растворами и водой для различных этапов промывки (рисунок 4).


Figure 4 - Tunnel chemical preparation
surface of aluminum profiles [2]

Современные туннели химической подготовки применяют каскадное движение воды и растворов сверху туннеля вниз (рисунок 5). The method of cascade flow of water and the solution was allowed to exclude the use of hundreds of nozzles, which have been used previously. This saves electricity, which was spent on numerous pumps, and also to reduce the consumption of chemicals for working solutions. Moreover, reduced maintenance costs for cleaning, adjustment, наладке и замене многочисленных спрейерных форсунок [3].



Figure 5 – Каскадная система подачи растворов и промывочной воды [2]

Oven drying sections

The profiles are located out of the tunnel wet the surface preparation and therefore before application of the powder require thorough drying. So they come in a drying oven, in which the hot air circulates. The air circulation system is arranged in such a way, to quickly dry the moisture from all surfaces of the profiles.

Powder paint spraying cabin

Напыления порошка происходит в специальной кабине (рисунок 6), which is on 10 by 20 sputter guns. Cab connected to a powder recycling system, that allows you to use a powder with an efficiency of up to 98 % [1, 2].



Figure 6 – Кабина напыления порошковой краски [2]

Sometimes line vertical powder coating include more than one, а две или даже три [1] кабины напыления порошка. In this case, you can speed the transition from one color to another color of paint. While one cabin goes clean for color change, It is running another cabin. This system allows up to 20 смен цвета в смену (рисунок 7) [1].


Figure 7 – Смена цвета для малой партии (6 профилей) желтого цвета
на вертикальной линии с тремя кабинами напыления [1]

polymerization oven

Profiles with sprayed powder fed into the polymerization oven. Usually this gas convection or electric infrared. The treatment temperature profiles in the furnace is from polymerization 160 by 210 ° C depending on the type of powder paint, and treatment duration - about 20 minutes.

Unloading of finished profiles

After exiting the curing oven conveyor is ready, but hot enough long profiles by, that upon arrival to the place of unloading, they had time to cool down to normal temperature for manual unloading of the conveyor.

conclusion

The technology and equipment for the application of powder coating aluminum profiles can have their own characteristics and differences depending on various production conditions. Vertical powder coating line is usually used for fairly large productions. The modular principle of technology and the use of the equipment will allow to take into account all the needs and characteristics of specific manufacturers, are applied powder coatings for aluminum profiles.

Sources:

1. Joseph C. Benedyk – LIGHT METAL AGE, OUR 2006
2. http://www.euroimpianti.ru/sistemy/sistemy-dlya-pokraski-alyuminiya/eurovertical
3. https://www.pfonline.com/articles/quality-italian-style